1. Field of Invention
The present invention relates to a pixel structure. More particularly, the present invention relates to a pixel structure using polymer-stabilized alignment.
2. Description of Related Art
In response to the increasing demand of displays, the industry put efforts in the development of the display. Among the displays, the cathode ray tube (CRT) has occupied the display market for many years, due to its high display quality and mature technology. However, the rising “environmental protection” awareness is against its power consumption and radiation disadvantage, and the limited flattening capability is against the market demands, and thus the cathode ray tube (CRT) cannot meet the market demands gradually. Therefore, the thin film transistor liquid crystal display (TFT-LCD), having superior properties such as high image quality, good space utilization, low power consumption, and no radiation, has become the mainstream display product of the market.
Currently, the market demands for the performance of LCDs includes high contrast ratio, no gray scale inversion, little color shift, high luminance, high color enrichment, high color saturation, fast response, and wide viewing angle. Technologies for achieving wide viewing angle comprises the twist nematic liquid crystal with wide viewing film, the in-plane switching (IPS) LCD, the fringe field switching LCD, and the multi-domain vertically alignment (MVA), etc.
FIG. 1A is a schematic sectional view of a conventional MVA LCD panel, and FIG. 1B is a top view of a TFT array substrate of the LCD panel as shown in FIG. 1A, wherein the schematic sectional view of the TFT array substrate in FIG. 1A is taken along the section line A-A′ in FIG. 1B. Referring to FIGS. 1A and 1B, the conventional MVA LCD panel 10 comprises a TFT array substrate 20, a color filter substrate 30, and a liquid crystal layer 40. The liquid crystal layer 40 is disposed between the TFT array substrate 20 and the color filter substrate 30.
The color filter substrate 30 comprises a glass substrate 31, a color filter layer 32, a common electrode 33, and a plurality of protrusions 34. The color filter layer 32 is disposed over the glass substrate 31. The common electrode 33 is disposed on the color filter layer 32. The protrusions 34 are disposed on the common electrode 33.
The TFT array substrate 20 comprises a glass substrate 21, a plurality of scan lines 22, a plurality of data lines 23, a plurality of TFTs 24, a plurality of transparent electrodes 25, and a plurality of common lines 26. The scan lines 22 and the data lines 23 are disposed on the glass substrate 21. Each of the TFTs 24 is electrically connected to one of the scan lines 22 and one of the data lines 23, respectively. Each of the transparent electrodes 25 is electrically connected to one of the TFTs 24, respectively, and crosses one of the common lines 26.
It should be noted that the transparent electrodes 25 have a plurality of slits 25a. The slits 25a together with the protrusions 34 make liquid crystal molecules in the liquid crystal layer 40 being inclined in multiple directions, such that the scope of viewing angle of the MVA LCD panel 10 is increased. Therefore, the MVA LCD panel 10 meets the requirement of wide viewing angle.
Though the scope of viewing angle of the MVA LCD panel 10 can be increased by the slits 25a together with the protrusions 34, when the MVA LCD panel 10 displays images, the color wash-out still occurs if the MVA LCD panel 10 is viewed at a large angle.